The present invention relates to a runflat tire capable of being safely and continuously driven for a relatively long distance in a deflated condition that the tire has lost air pressure due to a puncture, and more particularly to a runflat tire having an improved ride comfort performance in normal running without impairing the durability of tire in runflat mode.
A runflat tire is known as a tire which can be safely driven a certain distance at a relatively high speed in a deflated condition that the tire has lost air pressure due to a puncture or the like. Such a running is hereinafter referred to as “runflat running”. A runflat tire of this kind is provided with a sidewall-reinforcing rubber layer having a crescent-shaped cross section in a sidewall portion thereof. When it is deflated, the sidewall-reinforcing rubber layer supports the weight of a vehicle to prevent the tire from collapsing.
However, runflat tires of this kind have the disadvantage of being poor in ride comfort performance in normal running where the tires are inflated by a proper air pressure. In order to solve such a problem, it is conceivable to form the sidewall-reinforcing rubber layer from a soft rubber and/or to decrease the thickness of the sidewall-reinforcing rubber layer, but the runflat durability is decreased thereby.
Accordingly, it is an object of the present invention to provide a runflat tire, the ride comfort performance of which is improved without impairing the durability of the tire in runflat mode.
This and other objects of the present invention will become apparent from the description hereinafter.